Aidan O'Brien's Derby prospect Coliseum is out for the season after picking up a knee injury.
The Sadler's Wells colt, a winner at Cork this month, was taken out of the Derrinstown Derby Trial yesterday and O'Brien said: "He's had a setback and I think he will find it hard to come back this season."
Coliseum was runner-up in the National Stakes and the Acomb Stakes last year as well as fourth in Longchamp's Grand Criterium.
O'Brien had a more positive update about his 2,000 Guineas prospect, Orpen, who will work tomorrow morning.
"He is doing everything very well at the moment and I'm very happy with him. If we decided to run him in the 2,000 Guineas, he could go straight for Newmarket," he added.
The Ballydoyle two-year-olds have started with a bang this season and the latest to appear will be the Nureyev colt, Fasliyev, in the opener at Leopardstown on Sunday.
The Listowel track's chances of passing a 12.30 inspection today are described as "slim". A three-day meeting is scheduled to start tomorrow but snow fell on Tuesday night and rain yesterday morning, and the course manager Brendan Daly said: "I think there's only a slim chance of racing."
Almost four inches of snow fell on Leopardstown, which is scheduled to race on Sunday, but it had cleared by yesterday afternoon.
Mujahid, the 3 to 1 favourite for the 2000 Guineas, is not certain to reappear as planned in the City Index Craven Stakes at Newmarket today if the ground turns soft.
In a statement yesterday, Sheikh Hamdan's racing manager Angus Gold said: "Both Mujahid and Mutaahab have been declared for the Craven Stakes but Mutaahab will only run if Mujahid does not."
